+ AA6YQ comments below

I have a different issue, on importing 18853 from Log4OM, 17712 have JJ00aa in grid1 field. They are not duplicate QSO. All earlier QSOs have also been filled with this grid.
I then cleaned up all the records with JJ00aa. imported it to a new DXLab suite installed on a different PC. Even then on working a new station not worked earlier this was appearing. Again not on all QSOs.

+ So that I can see what's going on, please attach the ADIF file of 18853 QSOs that you exported from Log4OM to an email message, and send the message to me via

aa6yq (at) ambersoft.com

73,

Dave, AA6YQ